Vacuum filtration is a process of separating the solid from liquids. A Buchner funnel and side arm flask is used for this process. The filter paper is placed on the Buchner funnel, the size of the filter paper should fit on the funnel and should cover all the holes. To obtain the correct yield of the solid product from the vacuum filtration process, there should be no gaps around the edges of the filter paper as if there are any gaps around the edges of the filter paper, the solid precipitate will pass through the gaps with liquid and thus, results in the low percentage yield of the solid compound.
Hence, to obtain the correct yield percentage of the solid compound there should be no gaps around the edges of the filter paper during the vacuum filtration.